Jump to content
The Computer Audiophile

Misleading Measurements

Recommended Posts

1 hour ago, pkane2001 said:

But then, the question is what is it?

 

I suspect it is differing levels of phase/timing sensitivity.  I'm definitely a phase/point source guy (on steroids) and have optimized my system around same. I've noted that when folks come over, some people are definitely more WOW for phase-related optimizations, and others barely hear them at all.  The later group seems to be more power/amplitude focused.  Some folks fall somewhere in between.

 

 

Share this post


Link to post
Share on other sites
3 minutes ago, ray-dude said:

 

I suspect it is differing levels of phase/timing sensitivity.  I'm definitely a phase/point source guy (on steroids) and have optimized my system around same. I've noted that when folks come over, some people are definitely more WOW for phase-related optimizations, and others barely hear them at all.  The later group seems to be more power/amplitude focused.  Some folks fall somewhere in between.

 

I guess the question is what phase differences are we talking about? A linear filter, by definition, will only introduce a constant delay. That same delay will be in both stereo channels, so the effect is inaudible while the music is playing. Unless you need to sync playback to video or to other devices that have a different delay, a linear filter shouldn't cause any phase issues. Of course, a filter could be poorly implemented, or some devices may use non-linear filters. In those case, I think it'll be worth testing for the audibility of the phase differences.

Share this post


Link to post
Share on other sites
1 hour ago, ray-dude said:

As a practical matter, in my room, ~1mm changes in speaker position is audible for me in this (very) artificial scenario (and since this is an objective forum, distance from my listening position to the same position on speaker drivers confirmed to be identical to within the ~2mm resolution of my laser measure

 

You do realize that you'll need to keep your head to ~1mm exact position in order to keep this precise phase alignment? Do you use a head vise? 😎

 

1 hour ago, ray-dude said:

If we were to naively translate that to frequency, at the speed of sound that implies ~340kHz hearing resolution.  My 53 year old ears tap out around 15kHz and clearly can not hear >300kHz tones.  However, I can hear phase timing differences with that level of signal timing resolution, in this (very) artificial scenario.  With a better treated room, I'm sure things would be much better still.

 

Actually, timing resolution has little to do with sampling frequency. A 44.1kHz/16bit redbook CD standard is fully capable of resolving timing differences well below 1µs, and higher resolution has more to do with the number of bits than the sampling frequency. Meanwhile, the lowest audible interaural time difference (ITD) reported in literature is 10µs, in other words, well within the capabilities of the redbook standard.

 

1 hour ago, ray-dude said:

For me, higher resolution sources (whether natively recorded or reconstructed with a sinc reconstruction function) has been about phase timing accuracy, not audibility of the ultra high frequencies.  Depending on the recording chain and performance of the components, that phase resolution may or may not matter obviously.

 

I understand your preference for hi-res, but I'm afraid it's not needed for higher phase resolution. 

 

 

 

Share this post


Link to post
Share on other sites

 

The head vice would be fabricated out of panzeholz ;)  For the spirit of this anecdote, I was trying to share what is detectable, (thankfully) not how I listen.  FWIW, it is angular distance from the driver.  That is a LOT of lateral head position to have 1mm impact on distance to driver (at 9' listening distance, ~3" if I did my math right?).   My head twist variance is absolutely more than 1mm, agreed.  Interestingly, I find that my head position naturally gravitates to where the soundstage is most expansive and natural (or in the case of the pink noise scenario, where the null is more pronounced)

 

To the ITD, you are certainly better read on this than I am, but isn't that related to localization of sound source by the time difference it takes for sound to get to each ear?  With stereo music reproduction, we actually don't want to hear the speaker driver, we want a sound stage projected before us.  My phase analogies were related to that sound stage projection, not localizing where a speaker may be.  

 

That being said, I am google-level ignorant on the ITD measures.  I have no idea if the psycho acoustics are the same mechanism between ITD for sound source localization, and reconstructing a sound scape from the aggregate phases of the sounds we are hearing.  I suspect our brains are doing a lot of interpolation/projection for the later functions, just because our brains are really good at casting things in a way where it is easier to digest/interpret (Coltrane obviously isn't standing in front of me, but damn does my brain gets a lot of juice when it sounds like he is...sign me up for more of that kind of self-delusion!).

 

 

Share this post


Link to post
Share on other sites
1 hour ago, ray-dude said:

 

To the ITD, you are certainly better read on this than I am, but isn't that related to localization of sound source by the time difference it takes for sound to get to each ear?  With stereo music reproduction, we actually don't want to hear the speaker driver, we want a sound stage projected before us.  My phase analogies were related to that sound stage projection, not localizing where a speaker may be.  

 

That being said, I am google-level ignorant on the ITD measures.  I have no idea if the psycho acoustics are the same mechanism between ITD for sound source localization, and reconstructing a sound scape from the aggregate phases of the sounds we are hearing.  I suspect our brains are doing a lot of interpolation/projection for the later functions, just because our brains are really good at casting things in a way where it is easier to digest/interpret (Coltrane obviously isn't standing in front of me, but damn does my brain gets a lot of juice when it sounds like he is...sign me up for more of that kind of self-delusion!).

 

 

 

One area where misleading measurements certainly figure is that the quality of the audio reproduction is largely ignored, say in worrying about the precision of phase alignment. The rule in my book is very simple: the lower the overall, subjective, accuracy of the replay, the more factors like perfect phase alignment will matter, as regards getting impressive soundstaging happening - this was something I learned over 3 decades ago; if the SQ falls below a certain, quite precise standard, then the holographic qualities of the presentation evaporate - the mind no longer has enough information to 'interpolate', to maintain the reconstruction within one's head. It's quite staggering how capable the brain is in reconciling "what it all means" - I was amazed at the time at how powerful the illusion was - this can be pushed to the point that it becomes completely impossible to localise the speaker, no matter how ridiculous a place you move your head in an attempt to "hear the drivers working".

 

The simplistic measuring of our ears responding to phase anomalies completely misses the point that the brain has remarkable ability to interpret the data, when it has meaning - that is, it's a reproduction of music being played. With the obvious corollary ... surely this behaviour of human hearing should be exploited, to achieve maximum value in the situation?


Frank

 

http://artofaudioconjuring.blogspot.com/

 

 

Over and out.

.

 

Share this post


Link to post
Share on other sites

This is very true.  I experience a very abrupt phase transition where some recordings suddenly seem very real.  Some recordings never get there, others get on the "good side" of reality mountain after some significant effort or enhancement.  I've attributed this to my brain getting better at fabricating the illusion for me, once appropriate auditory cues are there.  Conversely, for recordings on edge of that transition, it is a very sensitive "tell" when I've done something to disrupt some aspect of music reproduction.   In a way, much of my audio optimization journey has been about getting more and more of my music library to feel like it is "real" and in the room.

 

Share this post


Link to post
Share on other sites
16 minutes ago, ray-dude said:

This is very true.  I experience a very abrupt phase transition where some recordings suddenly seem very real.  Some recordings never get there, others get on the "good side" of reality mountain after some significant effort or enhancement.  I've attributed this to my brain getting better at fabricating the illusion for me, once appropriate auditory cues are there.  Conversely, for recordings on edge of that transition, it is a very sensitive "tell" when I've done something to disrupt some aspect of music reproduction.   In a way, much of my audio optimization journey has been about getting more and more of my music library to feel like it is "real" and in the room.

 

 

Spot on. You're following the very methodology that I've been using for decades - nice to come across fellow travellers, 😁.


Frank

 

http://artofaudioconjuring.blogspot.com/

 

 

Over and out.

.

 

Share this post


Link to post
Share on other sites
4 minutes ago, pkane2001 said:

 

Realistic reconstruction of a complex soundscape with precise object placement is a much more complex topic that involves head tracking, head-related transfer function (HRTF), reflections/reverb, dynamic frequency effects, as well as ITD and ILD. Simple two channel/two speaker stereo can't reproduce a complex soundscape in a truly believable fashion.

 

 

 

That's the book learnin' explanation - but is not the reality. Anyone who has managed to evolve audio playback to the necessary quality knows what happens - it's quite trivial for an immensely complex soundscape to be perceived as being truly believable, at this standard of SQ.


Frank

 

http://artofaudioconjuring.blogspot.com/

 

 

Over and out.

.

 

Share this post


Link to post
Share on other sites
Just now, fas42 said:

 

That's the book learnin' explanation - but is not the reality. Anyone who has managed to evolve audio playback to the necessary quality knows what happens - it's quite trivial for an immensely complex soundscape to be perceived as being truly believable, at this standard of SQ.

 

Sorry, Frank, but that's false. Not just from books, but from my own experience. If you've not heard a properly instrumented 3-D audio with HRTF adjustment and head tracking, you should try it. There's no comparison to your "imagined" soundscape.

Share this post


Link to post
Share on other sites
38 minutes ago, pkane2001 said:

 

Sorry, Frank, but that's false. Not just from books, but from my own experience. If you've not heard a properly instrumented 3-D audio with HRTF adjustment and head tracking, you should try it. There's no comparison to your "imagined" soundscape.

 

Don't you appreciate that there are multiple ways "for the mind to be tricked"? It can be done with the deliberately manipulated process you mentioned - or by having the clues available by a very high standard of playback. The soundscapes "inside the skull" are the same - if your mind decides that what you hear is the "real thing" then it hangs on to the illusion; and won't give it up readily ... you see, everything is "imagined" - our minds, internally, don't put instances "created by science" on a pedestal.


Frank

 

http://artofaudioconjuring.blogspot.com/

 

 

Over and out.

.

 

Share this post


Link to post
Share on other sites
44 minutes ago, fas42 said:

 

Don't you appreciate that there are multiple ways "for the mind to be tricked"? It can be done with the deliberately manipulated process you mentioned - or by having the clues available by a very high standard of playback. The soundscapes "inside the skull" are the same - if your mind decides that what you hear is the "real thing" then it hangs on to the illusion; and won't give it up readily ... you see, everything is "imagined" - our minds, internally, don't put instances "created by science" on a pedestal.

 

I do, and I also know that each mind and ear combination is different. When you claim you hear "realistic" soundscape it means absolutely nothing to me, since I don't know what it takes to trick your mind into believing something like this. Maybe your imagination is much better than mine. Or maybe your definition of realistic is not the same as mine. Or maybe your brain never adjusted to use your HRTF for sound location and compensated by using some other method, maybe ITD/ILD only. Or...? I can't see (or hear) into your mind Frank, so I can't tell what you can hear and what is enough to fool you.

 

With my system, I hear a very good approximation to a soundstage with very good tonal reproduction, with excellent dynamics. I hear depth and position of instruments, and I enjoy it immensely,  and have for about 20 years with only minor changes. And yet, it's not producing a real soundscape. I only occasionally (and mostly on binaural content) hear voices and noises that startle me, surprise me to the point of thinking it's coming from inside the house rather than from the audio system. I almost never hear the sound coming from my speakers, unless the sound is panned to be exactly at the speaker position. Most of the left-to-right sounds come from in between, with some coming outside the speakers. The soundstage depth is amazing on some content, and goes a bit in front of the speakers on other. But sounds never get close to me. They never envelope me to the degree that I can move my head around and feel like I'm there. That's what proper 3-D soundscape reconstruction does. It's the difference between a very good 2-D photograph and the 3-D world. At least to me.

 

 

Share this post


Link to post
Share on other sites
32 minutes ago, pkane2001 said:

 

I do, and I also know that each mind and ear combination is different. When you claim you hear "realistic" soundscape it means absolutely nothing to me, since I don't know what it takes to trick your mind into believing something like this. Maybe your imagination is much better than mine. Or maybe your definition of realistic is not the same as mine. Or maybe your brain never adjusted to use your HRTF for sound location and compensated by using some other method, maybe ITD/ILD only. Or...? I can't see (or hear) into your mind Frank, so I can't tell what you can hear and what is enough to fool you.

 

Why I'm certain that it has nothing to do with 'conscious imagining' is because of the behaviour of that first good rig, nearly 35 years ago. I could easily have the system be in, and out, of the right quality zone, any number of times during the day; I was in full control of a sequence of actions that allowed this to happen - when "out" of the necessary quality zone, all I got was quite decent stereo, the same thing that most people get ...

 

Other people around me have appreciated the difference it made - which confirmed that I was not alone in hearing this ... people who couldn't give a damn about audiophile concerns just enjoyed listening to it; it "ticked the boxes".

 

32 minutes ago, pkane2001 said:

 

With my system, I hear a very good approximation to a soundstage with very good tonal reproduction, with excellent dynamics. I hear depth and position of instruments, and I enjoy it immensely,  and have for about 20 years with only minor changes. And yet, it's not producing a real soundscape. I only occasionally (and mostly on binaural content) hear voices and noises that startle me, surprise me to the point of thinking it's coming from inside the house rather than from the audio system. I almost never hear the sound coming from my speakers, unless the sound is panned to be exactly at the speaker position. Most of the left-to-right sounds come from in between, with some coming outside the speakers. The soundstage depth is amazing on some content, and goes a bit in front of the speakers on other. But sounds never get close to me. They never envelope me to the degree that I can move my head around and feel like I'm there. That's what proper 3-D soundscape reconstruction does. It's the difference between a very good 2-D photograph and the 3-D world. At least to me.

 

 

 

This clarifies to some degree ... direct sounds, the actual noise makers, never get close to one; they always remain beyond the vertical plane that the speakers lie in. What envelopes one is the reverberation of that direct sound from other surfaces in the listening area - exactly the same as listening in a concert hall; you never feel that you are in the middle of the orchestra - that's always in front of you, but the sound of the music fills the space you're in ... it's "immersive". I have no interest in having some instrument sounding like its coming from behind me; that's gimmicky, and has nothing to do with what listening to live music is like.

 

An almost perfect analogy is slicing off your listening room vertically at the plane of the speakers; and moving the remaining area, where the listeners are, to the place where the performance was being recorded. One can move around in the listening area as much as you like, and one always hears what an actual real world version of building something like this would be like.

 

 


Frank

 

http://artofaudioconjuring.blogspot.com/

 

 

Over and out.

.

 

Share this post


Link to post
Share on other sites
10 minutes ago, fas42 said:

Other people around me have appreciated the difference it made - which confirmed that I was not alone in hearing this ... people who couldn't give a damn about audiophile concerns just enjoyed listening to it; it "ticked the boxes".

 

I've had plenty of people say they love my system over the years. A few actually became audiophiles after listening to it, so you could say that it ticked at least some of the boxes. I'm not sure that proves anything 🤷‍♂️ 

 

I see that Alex is getting upset that we are veering off topic, so I'll stop here ;)

 

 

Share this post


Link to post
Share on other sites
1 hour ago, pkane2001 said:


 

 

Deleted.


How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file.

PROFILE UPDATED 28-06-2020

Share this post


Link to post
Share on other sites
3 hours ago, pkane2001 said:

I see that Alex is getting upset that we are veering off topic, so I'll stop here ;)

 

 

I seem to recall it was about

 

On 6/29/2020 at 10:42 AM, The Computer Audiophile said:

I would love to know why objective people are interested in anything below the threshold of human hearing and why they are interested in this info given that it can cause the same issues they rail against with respect to subjective opinions. 
 

Perhaps I should ask @Archimago why he publishes measurements below the threshold of human hearing. 

 


Sound Minds Mind Sound

 

 

Share this post


Link to post
Share on other sites
52 minutes ago, pkane2001 said:

 

The goal is simple: let the consumer pick a device based on features, build quality, engineering, price, esthetics, etc. As long as the consumers are aware that there's no audible difference, they can concentrate on other qualities that matter to them. There's no double standard in @Archimago's work, as far as I can see.

 

What about USB cables? Do you put them into the same category as DACs if all the cables and DACs have no differences above the threshold of human hearing? 


Founder of Audiophile Style

Announcing Polestar | Quick Community Reviews and Ratings

Share this post


Link to post
Share on other sites
1 minute ago, pkane2001 said:

 

Can you please show me where the highlighted statement has been made and why do you think that all objectivists think this? Of course there are poorly designed DACs and badly constructed cables that cause obvious, likely audible, distortions and errors.  That's why measurements are useful.

 

Armed with some knowledge about distortion audibility and with detailed measurements of a device, anyone can decide for themselves whether the device is fit for their consideration. I wouldn't consider a DAC with THD of 0.1% as transparent, for example.

Hi Paul, I think I used the wrong terms in my question. I don't think anyone has ever said it how I wrote it. That was my mistake.

 

I'll rephrase my question.

 

What about USB cables? Do you put them into the same category as DACs if the cables and measured DACs have no anomolies above the threshold of human hearing? 


Founder of Audiophile Style

Announcing Polestar | Quick Community Reviews and Ratings

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



×
×
  • Create New...